全文获取类型
收费全文 | 404篇 |
免费 | 14篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 5篇 |
综合类 | 10篇 |
化学工业 | 2篇 |
金属工艺 | 17篇 |
机械仪表 | 73篇 |
建筑科学 | 80篇 |
矿业工程 | 4篇 |
能源动力 | 15篇 |
轻工业 | 5篇 |
水利工程 | 12篇 |
石油天然气 | 8篇 |
武器工业 | 4篇 |
无线电 | 21篇 |
一般工业技术 | 17篇 |
冶金工业 | 1篇 |
原子能技术 | 9篇 |
自动化技术 | 143篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 4篇 |
2021年 | 3篇 |
2020年 | 9篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 9篇 |
2016年 | 12篇 |
2015年 | 12篇 |
2014年 | 19篇 |
2013年 | 21篇 |
2012年 | 27篇 |
2011年 | 25篇 |
2010年 | 18篇 |
2009年 | 20篇 |
2008年 | 22篇 |
2007年 | 17篇 |
2006年 | 26篇 |
2005年 | 20篇 |
2004年 | 19篇 |
2003年 | 21篇 |
2002年 | 24篇 |
2001年 | 15篇 |
2000年 | 13篇 |
1999年 | 11篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 9篇 |
1995年 | 9篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有426条查询结果,搜索用时 592 毫秒
21.
The increasing diffusion of services enabled by Internet of Things (IoT) technologies raises several risks associated to security and data quality. Together with the high number of heterogeneous interconnected devices, this creates scalability issues, thereby calling for a flexible middleware platform able to deal with both security threats and data quality issues in a dynamic IoT environment. In this paper a lightweight and cross-domain prototype of a distributed architecture for IoT is presented, providing minimum data caching functionality and in-memory data processing. A number of supporting algorithms for the assessment of data quality and security are presented and discussed. In the presented system, users can request services on the basis of a publish/subscribe mechanism, data from IoT devices being filtered according to users requirements in terms of security and quality. The prototype is validated in an experimental setting characterized by the usage of real-time open data feeds presenting different levels of reliability, quality and security. 相似文献
22.
23.
24.
《International Journal of Hydrogen Energy》2022,47(81):34492-34503
A search for efficient, durable, large-area, and economic catalyst material for low-cost production of hydrogen and oxygen is currently a high priority in the field of electrocatalysis (EC). In view of this, a cost-effective, earth abundant, highly stable, Pt free, and large-area (8 cm × 8 cm) bifunctional Ni–B electrocatalyst is reported via simple and economic SILAR method. A highly porous surface of Ni–B film with high surface wettability indicated better electrochemical water-splitting properties for the films and is obtained at 100 cycles. A Low over-potential value to obtain HER (49 mV) and OER (340 mV) at 10 mA/cm2 current suggested that they are comparable to the well-known Pt and RuO electrodes in alkaline medium (1M KOH), respectively. In actual water-splitting setup having Ni–B film (as cathode) and stainless steel (as anode), the hydrogen production of 612 ml/h is obtained at constant potential, which was enhanced by 18% i.e., 726 ml/h when a Ni–B film as both cathode and anode electrode was used. Both the electrodes are highly stable for over 15 days and interestingly they showed 7% increment in the EC performance. 相似文献
25.
对于大多数中国人来讲,奥斯瓦尔德·马蒂亚斯·翁格斯这个名字并不为人熟知,但在德国和欧洲地区,他是德国战后最重要的建筑师,也是德国新理性主义思潮的领军人物。其多产的一生为世人留下了大量伟大的建筑作品,他的创作思想深深影响了一大批欧洲建筑师。翁格斯的大多喜欢运用立方体等几何形体作为造型语汇,作品强调基于数字比例的严谨秩序,追求简化到极致的纯净形式,他的几所自宅尤其是后来的格拉斯舒特住宅和三号住宅都是他个人设计思想的最好体现。文章通过对格拉斯舒特住宅及三号住宅的对比分析,阐述了翁格斯追求纯粹几何形体的造型手法以及基于严谨数字比例的生成机制,探讨了背后蕴含的场所意义以及原型思想和古典精神。 相似文献
26.
27.
《Journal of Materials Processing Technology》2014,214(3):571-577
This study presents experimental results on the behavior of aluminum alloy metal foams with controlled pore morphology in compression. Two types of metal foams were analyzed, having uniform cell structure and with a dual-size cell arrangement seeking optimized mechanical properties. The structures were manufactured by lost-wax casting using 3D printed components for internal structure definition. Results for stiffness and energy absorption were obtained and compared on weight efficiency basis. The results are indicative of higher efficiency of the dual-size structures that may be considered for use in components subjected to impact or compression loading. 相似文献
28.
《低温学》2018
In order to cover long-term but small quantity liquid nitrogen requirements of laboratory or field users, a miniature movable mixed-refrigerant liquid nitrogen generator (MRLN) was developed and tested here, based on a precooled mixed-refrigerant J-T (MRJT) refrigerator. With the full air-cooled, skid-mounted structure, this MRLN was built utilizing off-the-shelf refrigeration components like commercial single-stage oil-lubricated compressors to reduce construction cost greatly. Bottled pure N2, pressure swing adsorption (PSA) unit and mini cryogenic rectification column could be employed to supply N2 in different operation modes respectively. In pure N2 mode, N2 was directly liquefied by the MRJT refrigerator. With feed N2 at 0.8 MPa, the specific power consumption (SPC) was 1.79 kWh L−1, and figure of merit (FOM) was 6.27%. The estimated SPC in PSA mode was 2.68 kWh L−1. For column mode, the SPC was 4.59 kWh L−1, with FOM of 3.38%. A closed N2 cycle could convey cooling capacity between flammable refrigerant and air. This MRLN could be a convenient and low-costing choice for some liquid nitrogen users. 相似文献
29.
景观文脉的传承始终是当代风景园林师关注的一大课题.现阶段,我国的园林建设面临盲目西化和符号化倾向,造成传统景观文脉严重缺失.该文在梳理建筑类型学核心理论的基础上,通过适用性分析,论证类型学方法对于解决文脉传承问题的有效性,进而将类型学方法移植至园林景观领域,结合我国的具体历史和地域文化条件,对类型学设计模式中的类型选择和类型转换进行了详尽的阐释和分析,旨在为现代园林设计中的景观文脉传承研究提供一种全新的思路. 相似文献
30.
论采矿CAD开发方法及环境与工具选择 总被引:3,自引:0,他引:3
文章简单回顾和总结了采矿CAD技术在我国发展的过程,现状及存在的问题。指出了进行采矿CAD开发方法及环境与工具选择研究的必要性和重要意义。在综合分析了我国具有代表性的采矿CAD软件的基础上,针对采矿工作的特点.建议采用原型化法进行开发。并注意选择与之相适应的环境与工具。AutoCAD为支持环境与工具进行二次开发是一种较为经济和理想的开发方法,值得推广提倡。 相似文献